Impaired absorption of cholesterol and bile acids in patients with an ileoanal anastomosis.
BACKGROUND
No data exist on cholesterol absorption in patients with an ileoanal anastomosis (IAA).


OBJECTIVE
To study cholesterol absorption and its effects on cholesterol and bile acid metabolism in patients with an IAA.


METHODS
Cholesterol absorption, and serum, biliary, and faecal lipids were studied in 24 patients with an IAA and 20 controls.


RESULTS
Fractional cholesterol absorption was significantly lower in the patients (36% versus 47% in controls). Surprisingly, the calculated intestinal influx of endogenous cholesterol was reduced so that the absolute absorption of cholesterol was decreased; elimination of cholesterol as faecal neutral steroids remained normal. Thus, the slightly increased cholesterol synthesis was mainly due to increased faecal bile acid excretion, which, in turn, was associated with reduced absorption and biliary secretion of bile acids. Serum total and low density lipoprotein (LDL) cholesterol and LDL triglycerides were lower in the patients. Molar percentage and saturation index of biliary cholesterol were slightly higher in patients with an IAA. Proportions of secondary bile acids in bile and faeces were diminished, and faecal unidentified bile acids were higher in patients.


CONCLUSIONS
Cholesterol absorption is significantly impaired in patients with an IAA, and is closely related to changes in serum and biliary lipids observed in these patients.
Hakala
K
K
Department of Medicine, University of Helsinki, Finland.
Vuoristo
M
M
Luukkonen
P
P
Järvinen
H J
HJ
Miettinen
T A
TA
D000328:Adult; D001003:Anal Canal / Q000601:surgery; D000714:Anastomosis, Surgical; D001647:Bile Acids and Salts / Q000032:analysis / Q000378:metabolism*; D002635:Chenodeoxycholic Acid / Q000032:analysis; D002784:Cholesterol / Q000096:biosynthesis / Q000097:blood / Q000378:metabolism; D002791:Cholesterol, Dietary / Q000493:pharmacokinetics*; D008078:Cholesterol, LDL / Q000097:blood; D002793:Cholic Acids / Q000032:analysis; D003093:Colitis, Ulcerative / Q000378:metabolism*; D005243:Feces / Q000737:chemistry; D005246:Feedback; D005260:Female; D006801:Humans; D007082:Ileum / Q000601:surgery; D007408:Intestinal Absorption; D008297:Male; D008875:Middle Aged; D016737:Proctocolectomy, Restorative; D014280:Triglycerides / Q000097:blood
D001647:Bile Acids and Salts; D002791:Cholesterol, Dietary; D008078:Cholesterol, LDL; D002793:Cholic Acids; D014280:Triglycerides; D002635:Chenodeoxycholic Acid; D002784:Cholesterol